To develop an interactive three-dimensional computer graphics system for applications in the analysis of the structures of large biological molecules, and of the interactions of these molecules with each other and with small molecules such as drugs. The ultimate goal is to understand biological function at the molecular level, and to apply this understanding to the design of more precise and efficient drugs for the treatment of disease. A further expected development will be in possible applications to the study of other complex biostructural problems, such as neuroanatomy. In neither of these fields, of very great importance to medicine, is there a better way to visualise the enormous complexities involved than by computer graphics.